While rare, there certainly can be times when you want less air flow to a room; but blocking HVAC vents can have adverse effects on the system. It can increase the pressure of airflow elsewhere.
The problem comes when people block up the airbricks, reducing airflow and along damp air to stay in the cavity. It may not immediately cause an issue indoor but there's a strong chance the stale air will cause floor timber to rot – an expensive problem to rectify.
Alternatively, you can hang a piece of artwork, photos, or trinkets over your air vent. However, it's worth noting that you shouldn't cover the air vent completely, always leaving a couple of inches exposed.
Blocked vents could cause carbon monoxide to build up in your home and cause carbon monoxide poisoning. A vent that has been blocked can also affect how yourfurnace works. It may run improperly or not at all when the intake or exhaustvent is blocked.
Because of humidity, moisture will collect behind the blocked vent, causing mold and mildew to not only fester, but to infect the air blowing through your entire house. This is a terrible scenario for any homeowner, but it can be especially dire for allergy and asthma sufferers.
Proper ventilation keeps the air fresh and healthy indoors. Like the lungs, homes need to be able to breathe to make sure that fresh air comes in and dirty air goes out. Air indoors can build up high levels of moisture, odors, gases, dust, and other air pollutants.
Ventilation is the exchange of fresh air from the outside and stale air and moisture from the inside of a property. Poor ventilation can result in harmful pollutants and moisture being trapped in the property which, in turn, can damage the health of people and the house itself.
That said, if you have an appliance that's causing carbon monoxide to leak into your home's attic or crawlspace, the carbon monoxide could potentially get sucked into the HVAC ducts through gaps, cracks, or holes. Your air conditioner would then send the carbon monoxide through the vents and into your home.
A blocked vent is a serious risk for house fires and should be dealt with immediately.
Fixed wall vents are found in older homes and are no longer required under building regulations. You can permanently seal the internal vent by filling it with caulking compound, plaster or sealants. A simple temporary solution is to cover the vent using a sheet of clear contact adhesive.
In the summer, when outdoor humidity is the highest, the foundation vents should be closed to keep the moisture out. In the winter, the idea is to open the vents to push damp air out and allow for circulation.
Wall ventilation and floor ventilation, as stipulated in Part C of the Building Regulations, are essential in preventing the build-up of stagnant air, mould and even potentially explosive gases.
It Leads to Costly Repairs
Since improper airflow adds so much stress to your system, it can lead to situations where very costly parts have to be replaced. For example, the coil can freeze over because temperature of the refrigerant isn't properly regulated. This can ruin the outdoor compressor.
If you smell a distinct or unpleasant odor from either your toilets or your sinks, it's possible that vent is clogged. Not only is it a gross smell, but methane is also something you don't want your family or customers breathing in. It's combustible, and it can also cause carbon monoxide poisoning.
Dust, dirt, and other allergens can build up in your air ducts over time and eventually be released into the air that you breathe. This can cause all sorts of respiratory problems, including sneezing, coughing, and watery eyes.
The best way to alert you and your family to unsafe levels of CO is to install a carbon monoxide detector. It works like a smoke alarm, sampling the air in your home and creating a loud alarm when levels of the gas are detected. It's important to evacuate your home immediately when your CO alarm sounds.
Inasmuch as there is need for good ventilation in our homes, opening a window will not completely get rid of carbon monoxide (Cannot stop carbon monoxide poisoning). The goal is to provide proper ventilation in our homes and reduce the possibility of carbon monoxide poisoning.
Carbon monoxide gas is odorless—it cannot be smelled. However, never ignore the “rotten egg” smell of natural gas. Try to find the source of the leak (often an unlit gas stove burner accidentally turned on while wiping down the stovetop).
Block Off the Vent: You can block the vent by placing a piece of furniture at the opening or purchasing a magnetic damper that's strong enough to stick to the steel on the wall or ceiling. Plastic sheeting can be placed over the opening as well.
Open vents create high levels of moisture, condensation, and humidity that will be detrimental to your home's foundation. According to a study by Advanced Energy, closed crawl space homes have used an average of 15% less energy for space conditioning.
Construction materials used in older homes can be damaged from too much moisture. Static vents, positioned throughout older homes, controlled moisture. In some older homes, wall air vents helped remove moisture build-up between exterior and interior walls.
Generally, the size of your home determines how many vents you will need per room. If your room is larger than 100 square feet, you will need more than one vent (at least two) to really get adequate airflow to the room. If the room is smaller, you only need one.
When temperatures drop below the freezing point, water pipes in the crawl space are bound to freeze if the vents remain open. It's a good practice to close off the vents in winter. Doing so prevents the dry, cold winter air from freezing the pipes inside the crawl space.